RAPD Variation in the Rare and Endangered Leucadendron Elimense (Proteaceae): Implications for Their Conservation.

We measured genetic variation of the three rare sub-species of the cone bush, Leucadendron elimense (Proteaceae), in comparison with a widespread, common species, Leucadendron salignum, using randomly amplified polymorphic DNA (RAPDs). Despite small population sizes and restricted distributions, study populations of L. elimense showed high levels of genetic variation in all three sub-species (0.24–0.34) with a genetic variation of 0.35 for the species as a whole. This was slightly higher than that measured for L. salignum (0.30), the most ubiquitous species of Leucadendron in the Cape flora. Analysis of molecular variance (AMOVA) indicated that most of the genetic variation lay among individuals within populations. We suggest several mechanisms whereby high levels of genetic variation might persist in small, isolated populations of rare Cape Proteaceae and propose that such taxa can be protected in a series of very small reserves at relatively low cost and minimal management input.